於
yúwūYū HSK6

in

于 (於) yú frequency
in preposition
expressing location or time (in, at, on)

他出生于一九九零年。

tā chū​shēng yú yī​jiǔ​jiǔ​líng​nián.

He was born in 1990.

to preposition
indicating a target, direction, or relation (to, toward, vis-à-vis, for)

他忠于自己的职守。

tā zhōng yú zì​jǐ de zhí​shǒu.

He is loyal to his duties.

than verb
used in comparison to indicate degree

质量优于数量。

zhì​liàng yōu yú shù​liàng.

Quality is better than quantity.

by preposition
used in the passive voice to introduce the agent

受制于人。

shòu​zhì yú rén.

To be controlled by others.

於 wū
oh proper name
literary interjection expressing exclamation or sighing

於！此情此景，真令我感叹万千。

wū! cǐ​qíng cǐ​jǐng, zhēn lìng wǒ gǎn​tàn wàn​qiān.

Alas! This scene truly fills me with endless emotions.

於 Yū
Yu
a Chinese surname

于教授是物理学方面的权威专家。

Yú jiào​shòu shì wù​lǐ​xué fāng​miàn de quán​wēi zhuān​jiā.

Professor Yu is an authoritative expert in the field of physics.

Frequency
Character
Written text
40th most common 3258.5 per million
Movie subtitles
181st most common 969.9 per million appears in 97% of films
Word
Movie subtitles
260.1 per million appears in 61% of films
Written text
851.5 per million

Details
HSK 3.0
Level 6
Simplified
于
Strokes
8
Unicode
U+65BC

Sources
Definitions
CC-CEDICT
Frequency data
MTSU Chinese text computingSUBTLEX-CHBCC Corpus (BLCU)